1. Field of the Invention
The present invention relates generally to the field of biotechnology. More particularly, it concerns novel methods and compositions for the generation of stable transfected cells.
2. Description of Related Art
To quickly generate large quantity of recombinant proteins or vaccines for both pre-clinical study and clinical trials, almost all drug development will face the same challenging obstacle of rapidly generating a high stable producer. Developing and identifying a stable cell line is a critical part of biopharmaceutical development. However, stable cell line development is a complicated process usually including transfection, selection, cloning/screening, comparison study, characterization and stability studies. Transfection is the first step of the process that will determine whether a stable cell line with high titer and good product quality can be generated within the required timeline. Many existing transfection methods have shown low transfection efficiency, like PEI and lipid methods, or low cell viability with moderate transfection efficiency with other EP methods (Tait 2004; Derouazi 2004; Reisinger 2009; Florea 2002). These two limiting factors resulted in the need of tedious, elaborate, time-consuming, and resource-intensive selection process. Commonly, several thousand clones will be screened to identify a good stable clone (Dharshanan 2011; Shi 2011) and expansive automation systems for both liquid handling and clone pick/selection such as Ambr™ system, ClonePix, FACS sorting and SimCell system (Dharshanan 2011; Shi 2011; Moses 2012; Lindgren 2009; Sleiman 2008; Carroll 2004; Thomas 2008) are invested and used by many pharmaceutical companies in this field. Others have also developed specific proprietary expression vectors and cell lines to generate high-yield stable cell line (de la Cruz 2006; Fan 2012; Nair 2011).